Meet Our Team

Boris Ratiner, MD
Boris Ratiner, MDFounder & Director

Dr. Ratiner finished Louisiana State University (LSU) School of Medicine in New Orleans, where he grew up. He then moved to San Francisco, where he finished Internal Medicine Residency followed by a Rheumatology Fellowship at University of California San Francisco (UCSF). In August of 1999, Dr. Ratiner took over a highly respected Rheumatology practice in the San Fernando Valley of Los Angeles. Dr. Ratiner is currently a Clinical Instructor of Rheumatology at UCLA and holds a teaching position at the Northridge Hospital Family Practice Residency Program and Cedars Sinai Medical Center. In addition, he is on the board and planning committee of the Arthritis Foundation.

Dr. Ratiner is also a frequent speaker at local hospitals to physicians and at community centers to patients on topics such as osteoarthritis, rheumatoid arthritis, gout, osteoporosis, lupus, and fibromyalgia. Dr. Ratiner has recently authored several book chapters on osteoarthritis and research papers on Hepatitis C arthritis. Dr. Ratiner is also fluent in Russian.

University of California San Francisco (UCSF)
Rheumatology Fellowship 1999, UCSF (Recertified in Rheumatology 2010)

regular CME attendance,
Clinical Instructor of Rheum Cedars/UCLA,
MS Ultrasound Course 2010,
So Cal Rheum Society lectures,
Tarzana Hospital Noon Conferences,
Monthly Journal Club Cedars/UCLA,
Weekly Journal Updates Review,
Yearly Lupus Review Course at ACR,
Yearly Rheumatoid Arthritis Therapy Update at ACR,
Yearly attendance at American College of Rheum meetings

Clinical Instructor, UCLA; Clinical Instructor,
Northridge Family Practice Residency
Staff Physician at West Hills Medical Center
Staff Physician at Providence Tarzana Medical Center

Jenny S. Oh, MD
Jenny S. Oh, MDStaff Physician

Dr. Oh grew up on the East coast. She received her Bachelor’s degree from Tufts University and earned her medical degree from State University of New York at Buffalo. Her professional pursuits brought her to Southern California where she finished her Internal Medicine residency and Rheumatology fellowship at University of Southern California, where she now also holds a teaching position as a Clinical Instructor.

At the urging of her patients, Dr. Oh has studied the medical benefits of Eastern medicine. She incorporates her knowledge in both Western and Eastern medicine in developing treatment plans that are unique to the individual patients’ needs.

University of Southern California (USC)
Rheumatology Fellowship, 2004, USC

So Cal Rheum Society lectures,
Tarzana Hospital Noon Conferences,
regular CME attendance,
Monthly Journal Club Cedars/UCLA,
Weekly Journal Updates Review

Clinical Instructor USC,
Clinical Instructor Northridge Hospital FP Program,
Staff Physician at Providence Tarzana Medical Center

Adam Kreitenberg, MD
Adam Kreitenberg, MDStaff Physician
  • Born and raised in Southern California, Dr. Kreitenberg received his Bachelor of Science (B.S.) from the University of California, Los Angeles (UCLA) in the field of Physiological Sciences. Traveling across the world, he received his medical degree at the prestigious Technion – Israel Institute of Technology in Haifa, Israel. 
  • Upon completing medical school, he relocated to Southern California where he finished his Internal Medicine Residency, followed by Rheumatology Fellowship, at the University of Southern California (USC) and Los Angeles County Medical Center.
  • Many of our rheumatology patients suffer from debilitating conditions such as osteoarthritis, rheumatoid arthritis, lupus, fibromyalgia, psoriatic arthritis and gout. As the newest addition to the practice, he possesses a fresh and unique approach to the practice of rheumatology.  He is extremely passionate and strives to combine his clinical training skills with the latest in rheumatology research advances to help improve patients’ quality of life.  Communication, as well as compassionate efficient care, are his strong-suits.
  • Dr. Kreitenberg is board certified in both internal medicine and rheumatology.  He has is currently seeing patients at several nearby hospitals in the San Fernando Valley including Northridge Hospital Medical Center and West Hills Hospital. He is fluent in English, Spanish and Hebrew 
  • Areas of interest:
    • Rheumatoid Arthritis
    • Osteoarthritis
    • Spondyloarthropathies
    • Lupus
    • Scleroderma
    • Mixed Connective Tissue Disease
    • Sarcoidosis
    • Osteoporosis
    • Gout
    • Inflammatory Myopathies
    • Vasculitis
Internal Medical Residency, University of Southern California (USC) Medical Center
Rheumatology Fellowship, University of Southern California (USC) Medical Center

Southern California Rheumatology Society Lectures
Providence Tarzana Medical Center, Noon CME Conferences
Northridge Hospital Medical Center, Noon CME Conferences

Spondylitis Association of America
Providence Tarzana Medical Center Grand Rounds
Larisa Magid
Larisa MagidPhysician Assistant

Larisa Magid received her degree in Microbiology from Odessa State University in Ukraine where she grew up. In 2003 she graduated from UC Davis PA/FNP program. She is fully licensed as a Physician Assistant in the state of California by the California Medical Board and certified by National Committee on Certification of Physician Assistants (NCCPA).

Ms.Magid has over 20 years experience in the medical field. Last 7 years she has been specializing in Rheumatology and working with Dr. Ratiner and Dr Oh at RTMC.

In 2009 she received her Masters degree in Advanced Physician Assistant Studies with emphasis in Rheumatology from A.T.Still University in Mesa, Arizona.

Larisa Magid is also fluent in Spanish and Russian.

Physician Assistant Graduate Program 2003, UC Davis
Advanced PA Studies in Rheumatology 2009, A.T.Still University

Weekly Journal Updates Review,
200 hr/yr of CME,
Osteoporosis Course Review,
Herbal Medication Comprehensive Review Course,

About Us

Rheumatology Therapeutics Medical Center is a comprehensive center, located in the Los Angeles area, that specializes in the treatment of diseases that affect joints, muscles, and bones. Many of these diseases also involve the immune system.

Our center is staffed by medical doctors board certified in Rheumatology and Internal Medicine and by allied health professionals that are experienced and caring. By offering on-site Rheumatology Consultative Services, X-ray, DEXA, MRI, Laboratory, Physical Therapy, Clinical Trials, and Infusion Services we make your total care convenient for you.

RTMC is located in San Fernando Valley of Los Angeles. The center is only one block off the 101 Freeway and one block off Ventura Boulevard. The center is also across the street from Providence Tarzana Hospital, a leading hospitals in Los Angeles. The area around the center also has multiple pharmacies, grocery and retail stores, as well as a multitude of multicultural restaurants.

In an effort to accommodate our patients we have assembled an all star international staff. Different languages spoken by our staff to accomodate you include: English, Spanish, Russian, Farsi, Tagalog, and Korean Hebrew, Armenian, Japanese, Ukrainian.